U.S. patent number 9,495,656 [Application Number 14/512,478] was granted by the patent office on 2016-11-15 for material handling method.
This patent grant is currently assigned to SAP SE. The grantee listed for this patent is Tobias Adler, Oliver Radmann. Invention is credited to Tobias Adler, Oliver Radmann.
United States Patent |
9,495,656 |
Adler , et al. |
November 15, 2016 |
Material handling method
Abstract
The present disclosure relates to a material handling method of
performing by means of an automatic mechanical material handling
equipment controlled by a control system at least a first and a
second access task for accessing respectively at least a first and
at least a second article stored in a material handling storage
system, the first and second access tasks having been assigned a
first and a second execution priority respectively. The method
comprises a) controlling the automatic mechanical material handling
equipment to perform the first access task having the highest
priority; and in parallel to performing the first access task a1)
evaluating data indicative of the material handling storage system
for determining that a first intermediate task is to be performed,
wherein the first intermediate task is required in order to perform
by the automatic mechanical material handling equipment the second
access task; and a2) assigning an execution priority to the first
intermediate task higher than the second execution priority; b)
controlling the automatic mechanical material handling equipment to
perform at least the first intermediate task and the second access
task according to the order of execution priorities.
Inventors: |
Adler; Tobias (Viernheim,
DE), Radmann; Oliver (Huffenhardt, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Adler; Tobias
Radmann; Oliver |
Viernheim
Huffenhardt |
N/A
N/A |
DE
DE |
|
|
Assignee: |
SAP SE (Walldorf,
DE)
|
Family
ID: |
55654965 |
Appl.
No.: |
14/512,478 |
Filed: |
October 13, 2014 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20160101937 A1 |
Apr 14, 2016 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G05B
13/00 (20130101); H01L 21/67259 (20130101); H01L
21/681 (20130101); G06Q 10/08 (20130101) |
Current International
Class: |
G06F
7/00 (20060101); G05B 13/00 (20060101); G06Q
10/08 (20120101) |
Field of
Search: |
;700/218 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
EPO, European Search Report, EP 14188607.7, Apr. 1, 2015. cited by
applicant.
|
Primary Examiner: Logan; Kyle
Attorney, Agent or Firm: Richardt Patentanwalte PartG m
Claims
The invention claimed is:
1. A material handling method of performing by means of an
automatic mechanical material handling equipment controlled by a
control system at least a first and a second access task for
accessing respectively at least a first and at least a second
article stored in a material handling storage system, the first and
second access tasks having been assigned a first and a second
execution priority respectively, the method comprising: a)
controlling the automatic mechanical material handling equipment to
perform the first access task having the highest priority; and in
parallel to performing the first access task; a1) evaluating data
indicative of the material handling storage system for determining
that a first intermediate task is to be performed, wherein the
first intermediate task is required in order to perform by the
automatic mechanical material handling equipment the second access
task; and a2) assigning an execution priority to the first
intermediate task higher than the second execution priority; b)
controlling the automatic mechanical material handling equipment to
perform at least the first intermediate task and the second access
task according to the order of execution priorities, wherein a
third access task for accessing a third article is assigned a lower
execution priority than the second execution priority, wherein the
second access task comprises an initialization and an execution
phase, the method further comprising: in parallel to performing the
second access task evaluating the data for determining that a
second intermediate task is to be performed before the third access
task; determining that the second intermediate task is dependent of
the first intermediate task such that the second intermediate task
is to be performed after the first intermediate task and before the
second access task and assigning an execution priority to the
second intermediate task accordingly; in case the second access
task is in the initialization phase pausing the automatic
mechanical handling equipment; and re-controlling the automatic
mechanical material handling equipment to resume and to further
perform the second intermediate task, the second and third access
tasks according to the order of execution of priorities.
2. The method of claim 1, wherein evaluating comprises: prompting a
user of the control system for a feedback on the second access task
using the data; and receiving from the user a feedback indicating
the first intermediate task.
3. The method of claim 1, wherein the evaluation is performed using
simulation data obtained by a simulation of the second access task
based on a model of the automatic mechanical handling equipment,
the control system and the automatic material handling storage
system, the simulation data being the data.
4. The method of claim 1, further comprising: controlling a camera
connected to the control system to collect image signals from the
material handling storage system, to analyze the collected image
signals and to provide the data as a result of the analysis.
5. The method of claim 1, wherein a task of the first and second
access tasks comprises at least one of: moving the respective
article from a source storage bin to a destination storage bin in
the material handling storage system; replacing the respective
article by one or more articles; tagging the respective
article.
6. The method of claim 1, wherein the evaluating comprises
determining that the second article is a defect article, wherein
the first intermediate task comprises a task of replacing the
second article with a respective non-defect article.
7. The method of claim 1, wherein the evaluating comprises
determining that the distance of the automatic mechanical material
handling equipment to the second article is higher than a maximum
reachable distance for having access to the second article, wherein
the first intermediate task comprises controlling the automatic
mechanical material handling equipment to move close to the second
article to form a distance to the second article smaller than the
maximum reachable distance.
8. The method of claim 1, wherein the control system is a
multiprocessor system, wherein the controlling the automatic
mechanical material handling equipment to move the first article
and the evaluating and assigning are executed by at least two
processors of the multiprocessor system.
9. The method of claim 1, wherein the second access task comprises
moving the second article from a first storage bin to a second
storage bin, wherein the evaluating comprises: determining the
movement path of the automatic mechanical material handling
equipment along which the second article is to be moved to the
second storage bin; using the data for determining that at least a
third article is stored in a storage bin that it is on the movement
path; defining the first intermediate task as a task for moving the
third article out of the movement path.
10. The method of claim 9, wherein the third article is given by
the first article after the movement of the first article is
performed, wherein the first intermediate task comprises recreating
the first access task using a different destination storage bin for
the first article and controlling the automatic mechanical material
handling equipment to perform the recreated first access task.
11. The method of claim 9, wherein the material handling storage
system comprises at least one pallet rack having at least one front
storage bin and one back storage bin in a front-to-back depth of
the pallet rack, wherein the second article is stored in the back
storage bin and is blocked for movement by the third article stored
in the front storage bin, wherein the first intermediate task
comprises moving the third article.
12. A material handling method of performing by means of an
automatic mechanical material handling equipment controlled by a
control system at least a first and a second access task for
accessing respectively at least a first and at least a second
article stored in a material handling storage system, the first and
second access tasks having been assigned a first and a second
execution priority respectively, the method comprising: a)
controlling the automatic mechanical material handling equipment to
perform the first access task having the highest priority; and in
parallel to performing the first access task; a1) evaluating data
indicative of the material handling storage system for determining
that a first intermediate task is to be performed, wherein the
first intermediate task is required in order to perform by the
automatic mechanical material handling equipment the second access
task; and a2) assigning an execution priority to the first
intermediate task higher than the second execution priority; b)
controlling the automatic mechanical material handling equipment to
perform at least the first intermediate task and the second access
task according to the order of execution priorities, the method
further comprising: determining a first idle time of inactivity of
the automatic mechanical material handling equipment before
performing b) and after the assigning; in response to a
determination that the first idle time is higher than a maximum
idle time threshold delaying execution of b) until receiving a
confirmation of the result of the evaluation.
13. The method of claim 12, further comprising determining a second
idle time of inactivity of the automatic mechanical material
handling equipment as being the idle time of inactivity of the
automatic mechanical material handling equipment when performing
a1)-a2) in series with a) and b) instead of parallel execution of
a1)-a2) to a), wherein the maximum idle time threshold comprises
the second idle time.
14. A non-transitory computer-readable medium, with instructions
stored thereon, which when executed by at least one processor of a
computing device, cause the computing device to control an
automated lift truck to perform at least a first and a second
warehouse order for moving at least a first and a second handling
unit located in a warehouse respectively, the first and second
warehouse orders being assigned a first and a second execution
priority respectively, the control comprising: determining the
first warehouse order for moving the first handling unit as the
warehouse order having the highest priority; controlling the
automated lift truck to move the first handling unit using the
first warehouse order; and in parallel to moving the first handling
unit: determining that the second warehouse order for moving the
second handling unit is the warehouse order having the subsequent
highest execution priority; and determining that an intermediate
warehouse order is required such that the second warehouse order
may be executed; creating the intermediate warehouse order and
assigning an execution priority to the intermediate warehouse
higher than the second execution priority; and controlling the
automated lift truck to move the second handling unit using the
second warehouse order after performing the intermediate warehouse
order, wherein the warehouse comprises at least one pallet rack
having at least one front storage bin and one back storage bin in a
front-to-back depth of the pallet rack, wherein the second handling
unit is stored in the back storage bin and is blocked for movement
by a third handling unit stored in the front storage bin, wherein
the intermediate warehouse order comprises a stock transfer task of
moving the third handling unit.
15. The non-transitory computer-readable medium of claim 14,
wherein determining of the intermediate warehouse order is
performed using data indicative of at least the storage bins and
the content of the storage bins of the at least one pallet
rack.
16. The non-transitory computer-readable medium of claim 14,
wherein determining of the intermediate warehouse order comprises
determining that the second handling unit is a defect handling
unit, wherein the intermediate warehouse order comprises a task of
replacing the second handling unit with a respective non-defect
handling unit.
17. The non-transitory computer-readable medium of claim 14,
wherein the first and second handling units are moved to one of a
storage bin of the warehouse and an aisle of the warehouse.
18. A control system for controlling an automatic mechanical
material handling equipment to perform at least a first and a
second access task for accessing respectively at least a first and
at least a second article stored in a material handling storage
system, the first and second access tasks having been assigned a
first and a second execution priority respectively, the control
system comprising: a hardware processor; a memory accessible by the
hardware with instructions stored thereon; and a hardware interface
for allowing the hardware processor to send messages to and receive
messages from one or more components of the automatic mechanical
material handling equipment; wherein, the instructions, when
executed by the hardware processor, cause the control system to
perform a method comprising: a) controlling the automatic
mechanical material handling equipment to perform the first access
task having the highest priority; and in parallel to performing the
first access task; a1) evaluating data indicative of the material
handling storage system for determining that a first intermediate
task is to be performed, wherein the first intermediate task is
required in order to perform by the mechanical material handling
equipment the second access task; and a2) assigning an execution
priority to the first intermediate task higher than the second
execution priority; and b) controlling the automatic mechanical
material handling equipment to perform at least the first
intermediate task and the second access task according to the order
of execution priorities, wherein a third access task for accessing
a third article is assigned a lower execution priority than the
second execution priority, wherein the second access task comprises
an initialization and an execution phase, the method further
comprising: in parallel to performing the second access task
evaluating the data for determining that a second intermediate task
is to be performed before the third access task; determining that
the second intermediate task is dependent of the first intermediate
task such that the second intermediate task is to be performed
after the first intermediate task and before the second access task
and assigning an execution priority to the second intermediate task
accordingly; in case the second access task is in the
initialization phase pausing the automatic mechanical handling
equipment; and re-controlling the automatic mechanical material
handling equipment to resume and to further perform the second
intermediate task, the second and third access tasks according to
the order of execution of priorities.
Description
FIELD OF THE DISCLOSURE
This invention relates to automated materials storage systems and
methods and more particularly to a material handling method.
DESCRIPTION OF THE RELATED ART
Manufacturing as well as distribution systems and storage
management systems have been moving toward material handling
automation for years in order to operate with minimal human
intervention. However, there is a continuous need to improve
materials handling automation namely processes and streamline
operations.
SUMMARY OF THE PRESENT DISCLOSURE
Various embodiments provide a material handling method and a
control system and an article handling system as described by the
subject matter of the independent claims. Advantageous embodiments
are described in the dependent claims.
In one aspect, the invention relates to a material handling method
of performing by means of an automatic mechanical material handling
equipment controlled by a control system at least a first and a
second access task for accessing respectively at least a first and
at least a second article stored in a material handling storage
system, the first and second access tasks having been assigned a
first and a second execution priority respectively. The method
comprises: a) controlling the automatic mechanical material
handling equipment to perform the first access task having the
highest priority; and in parallel to performing the first access
task a1) evaluating data indicative of the material handling
storage system for determining that a first intermediate task is to
be performed, wherein the first intermediate task is required in
order to perform by the automatic mechanical material handling
equipment the second access task; and a2) assigning an execution
priority to the first intermediate task higher than the second
execution priority; b) controlling the automatic mechanical
material handling equipment to perform at least the first
intermediate task and the second access task according to the order
of execution priorities.
In another aspect, the invention relates to a computer program
product comprising computer executable instructions to perform the
method steps of the preceding method.
In another aspect, the invention relates to a control system for
controlling an automatic mechanical material handling equipment to
perform at least a first and a second access task for accessing
respectively at least a first and at least a second article stored
in a material handling storage system, the first and second access
tasks having been assigned a first and a second execution priority
respectively, the control system being configured for: a)
controlling the mechanical material handling equipment to perform
the first access task having the highest priority; and in parallel
to performing the first access task a1) evaluating data indicative
of the material handling storage system for determining that a
first intermediate task is to be performed, wherein the first
intermediate task is required in order to perform by the mechanical
material handling equipment the second access task; and a2)
assigning an execution priority to the first intermediate task
higher than the second execution priority; b) controlling the
mechanical material handling equipment to perform at least the
first intermediate task and the second access task according to the
order of execution priorities.
In another aspect, the invention relates to an article handling
system comprising a mechanical material handling equipment and a
control system of the previous embodiment.
The mechanical material handling equipment comprises a programmable
logic controller.
In some embodiments a method of controlling picking operations of
at least a first and a second handling unit located in a warehouse
by means of an automated picking equipment controlled by a control
system, the control system comprising a first and second warehouse
order for moving the first and second handling units respectively,
the first and second warehouse orders having been assigned a first
and a second execution priority respectively. The method comprises
the steps performed by the control system of: determining the first
warehouse order for moving the first handling unit as the warehouse
order having the highest priority; controlling the picking
equipment to move the first handling unit using the first warehouse
order; and in parallel to moving the first handling unit
determining that the second warehouse order for moving the second
handling unit is the warehouse order having the subsequent highest
execution priority, and determining that an intermediate warehouse
order is required such that the second warehouse order may be
executed; creating the intermediate warehouse order and assigning
an execution priority to the intermediate warehouse higher than the
second execution priority; controlling the picking equipment to
move the second handling unit using the second warehouse order
after performing the intermediate warehouse order.
In some embodiments, a method of controlling picking operations of
at least a first and a second handling unit located in a warehouse
by means of an automated lift truck controlled by a control system,
the control system comprising a first and second warehouse order
(WO) for picking the first and second handling unit respectively,
the first and second warehouse orders having been assigned a first
and a second execution priority respectively. The method comprises
determining by the control system when a programmable logic
controller (PLC) is busy in confirming a previous warehouse order
what has to be executed next by the automated lift truck based on
the first and second execution priorities; checking by the control
system whether the handling unit (HU) of the first and second Hus
to be picked may be removed directly; creating an automatic stock
transfer WO to be executed next, if HU to be picked is blocked by
another HU; executing next WO by the automated lift truck when
previous WO is finished.
In some embodiments, a non-transitory computer-readable medium,
with instructions stored thereon, which when executed by at least
one processor of computing device, cause the computing device to
control an automated lift truck to perform at least a first and a
second warehouse order for moving at least a first and a second
handling unit located in a warehouse respectively, the first and
second warehouse orders being assigned a first and a second
execution priority respectively. The control comprises determining
the first warehouse order for moving the first handling unit as the
warehouse order having the highest priority; controlling the
automated lift truck to move the first handling unit using the
first warehouse order; and in parallel to moving the first handling
unit determining that the second warehouse order for moving the
second handling unit is the warehouse order having the subsequent
highest execution priority; and determining that an intermediate
warehouse order is required such that the second warehouse order
may be executed; creating the intermediate warehouse order and
assigning an execution priori-ty to the intermediate warehouse
higher than the second execution priority; controlling the
automated lift truck to move the second handling unit using the
second warehouse order after performing the intermediate warehouse
order.
According to one embodiment, the warehouse comprises at least one
pallet rack having at least one front storage bin and one back
storage bin in a front-to-back depth of the pallet rack, wherein
the second handling unit is stored in the back storage bin and is
blocked for movement by a third handling unit stored in the front
storage bin, wherein the intermediate warehouse order comprises a
stock transfer task of moving the third handling unit.
According to one embodiment, determining of the intermediate
warehouse order is performed using data indicative of at least the
storage bins and the content of the storage bins of the at least
one pallet rack.
According to one embodiment, determining of the intermediate
warehouse order comprises determining that the second handling unit
is a defect handling unit, wherein the intermediate warehouse order
comprises a task of replacing the second handling unit with a
respective non-defect handling unit.
According to one embodiment, the first and second handling units
are moved to one of a storage bin of the warehouse and an aisle of
the warehouse.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings illustrate the various embodiments and,
together with the description, further serve to explain the
principles of the embodiments and to enable one skilled in the
pertinent art to make and use the embodiments.
FIG. 1 is a schematic diagram illustrating a storage system.
FIG. 2 is a flow diagram illustrating an example material handling
method.
FIG. 3 is a flow diagram illustrating another example material
handling method.
FIG. 4 is a flowchart of an exemplary method for evaluating data
indicative of the automatic material handling equipment.
FIG. 5 is a flowchart of another exemplary method for evaluating
data indicative of the automatic material handling equipment.
FIG. 6 illustrates a method for picking handling units from a
multi-depth storage bins.
DETAILED DESCRIPTION
In the following, like numbered elements in the figures either
designate similar elements or designate elements that perform an
equivalent function. Elements which have been discussed previously
will not necessarily be discussed in later figures if the function
is equivalent.
The above features may have the advantage of reducing the idle time
of the control system as well as the automatic mechanical material
handling equipment. The idle time is the time during which the
control system or the automatic mechanical material handling
equipment is not used (or inactive).
Another advantage may be that the processing time required for
processing the tasks is reduced compared to conventional
methods.
Another advantage may be that the present method may be seamlessly
integrated in existing control systems since the logic of
determining or selecting a task with a highest priority and
controlling of the automatic mechanical material handling equipment
to perform the task is integrated with the present anticipation
method to definition tasks and execution priorities.
The method steps a)-a1)-a2)-b) are executed automatically.
The term "task" or "access task" or "warehouse order" refers to an
action to be performed by the automatic mechanical material
handling equipment. The task may comprise, for example, an
initializing or planning phase and/or an executing phase. The task
may be created as a logic program or set of instructions for
realizing an intended function. For example, the task may be
defined as a telegram that may be sent to a PLC that controls the
automatic mechanical material handling equipment to perform the
task.
The article may comprise for example a handling unit, a box, a
container, a product a material or any storable object or item in
the material handling storage system.
The first intermediate task may be a task that has to be performed
before the second access to be performed. The first intermediate
task may be another access task for accessing another article or
any other task related to the mechanical material handling
equipment and/or the material handling storage system.
The data indicative of the material handling storage system may be
stored in the control system. The data may be updated in a regular
basis e.g. when a change is occurred in the material handling
storage system or a task is performed in the material handling
storage system.
The control system may comprise a smartphone, a PDA, a laptop, a
computer system, and the like.
The material handling storage system may comprise a pallet rack to
store materials or, cartons or cases or articles on pallets (or
"skids"). The material handling storage system may be a multi-depth
storage system.
Steps a1)-a2) are performed in parallel to performing the first
access task means that steps a1)-a2) started while the first access
task is running. Steps a1)-a2) may end before at or after the first
access task is performed or ended.
The step b) may be performed in two stages. In the first stage, the
first intermediated task is determined or selected as the task
having the highest priority among the first intermediate task and
the second access task e.g. among non-executed tasks and the
automatic mechanical material handling equipment is controlled to
perform the first intermediated task. In the second stage, the
second access task is determined or selected as the task having the
highest priority among the second access task e.g. among
non-executed tasks and the automatic mechanical material handling
equipment is controlled to perform the second access task.
For example, steps a1)-a2) may be repeated in parallel to every
task being executed. For example, in parallel to performing the
second access task by the automated or automatic mechanical
material handling equipment a potential or eventual intermediate
task may be (pre) determined in advance such that the task
priorities may be reorganized. In this way, when the task being
executed is finished, the next task may be automatically determined
without extra delays that may be caused by the post-determination
(i.e. after the termination of the second access task being
executed) that the intermediate task is to be performed.
The automatic mechanical material handling equipment may comprise
an automatic lift truck or any other vehicle or equipment operable
to perform access tasks as described herein.
According to one embodiment, a third access task for accessing a
third article is assigned a lower execution priority than the
second execution priority, wherein the second access task comprises
an initialization and an execution phase. The method further
comprises in parallel to performing the second access task
evaluating the data for determining that a second intermediate task
is to be performed before the third access task; determining that
the second intermediate task is dependent of the first intermediate
task such that the second intermediate task is to be performed
after the first intermediate task and before the second access task
and assigning an execution priority to the second intermediate task
accordingly; in case the second access task is in the
initialization phase pausing the mechanical handling equipment; and
re-controlling the automatic mechanical material handling equipment
to resume and to further perform the second intermediate task, the
second and third access tasks according to the order of execution
of priorities. For example, in case the second access task is in
the execution phase a new task may be created to undo the second
access task (e.g. if an article is moved it may be moved back to
its original place etc.) and then the second intermediate task, the
second and third access tasks may be executed.
This may further reduce the idle time of the control system and the
automatic mechanical material handling equipment. Further, this
embodiment may have the advantage of providing an accurate
execution of the tasks.
According to one embodiment, the method further comprises
determining a first idle time of inactivity of the automatic
mechanical material handling equipment before performing step b)
and after the assigning step; in response to a determination that
the first idle time is higher than a maximum idle time threshold
delaying execution of step b) until receiving a confirmation of the
result of the evaluation.
For example, the result of the evaluation may be presented to a
user of the control system and the user may be prompted to provide
feedbacks on the result of the evaluation. This embodiment may have
the advantage of controlling the workflow of the present method
which may increase the accuracy of the tasks execution.
According to one embodiment, the method further comprises
determining a second idle time of inactivity of the automatic
mechanical material handling equipment as being the idle time of
inactivity of the automatic mechanical material handling equipment
when performing steps a1)-a2) in series with steps a) and b)
instead of parallel execution of steps a1)-a2) to step a), wherein
the maximum idle time threshold comprises the second idle time.
This may provide a reliable check since the idle time when
performing steps a1)-a2) in parallel to step a) may be smaller than
the idle time when they are performed in series with other
steps.
Parallel execution of steps a1)-a2) to step a) comprises executing
a1)-a2) in parallel to performing the first access task by the
automatic mechanical material handling equipment.
According to one embodiment, evaluating comprises prompting a user
of the control system for a feedback on the second access task
using the data; receiving from the user a feedback indicating the
first intermediate task.
For example, the data may be presented to the user in the form of a
map of the material handling storage system schematically showing
the content of the material handling storage system.
The user may comprise, in one example, a computer system or a
device that may communicate with the control system.
According to one embodiment, the evaluation is performed using
simulation data obtained by a simulation of the second access task
based on a model of the mechanical handling equipment, the control
system and the material handling storage system, the simulation
data being the data.
The simulation of the second access task may be performed on the
fly (online) or offline for producing the data that is
evaluated.
According to one embodiment, the method further comprises
controlling a camera connected to the control system to collect
image signals from the material handling storage system, to analyze
the collected image signals and to provide the data as a result of
the analysis. The method of this embodiment may be regularly
performed e.g. on a periodic basis or as soon as a task is
performed in the data indicative of the material handling storage
system.
According to one embodiment, a task of the first and second access
tasks comprises at least one of: moving the respective article from
a source storage bin to a destination storage bin in the material
handling storage system; replacing the respective article by one or
more articles; tagging the respective article. The task may further
comprise executing physical inventory counting. The task may
further comprise moving the respective article to a drop-off point
that may be another storage bin or other locations in the storage
system.
According to one embodiment, the second access task comprises
moving the second article from a first storage bin to a second
storage bin, wherein the evaluating comprises: determining the
movement path of the automatic mechanical material handling
equipment along which the second article is to be moved to the
second storage bin; using the data for determining that at least a
third article is stored in a storage bin that it is on the movement
path; defining the intermediate task as a task for moving the third
article out of the movement path. This may provide a reliable
picking system that may increase productivity compared to a
streamlining of the task creation and submission by the control
system.
According to one embodiment, the third article is given by the
first article after the movement of the first article is performed,
wherein the first intermediate task comprises recreating the first
access task using a different destination storage bin and
controlling the automatic mechanical material handling equipment to
perform the recreated first access task. In this case, the
execution priority of the first intermediate task may be the
execution priority of the first access task such that there is no
need to assign a new execution priority to the first intermediate
task. This may save resources required for determining new
priorities.
For example, the first article is moved to a position on the
movement path, and thus the third article is determined to be the
first article.
According to one embodiment, the evaluating comprises determining
that the second article is a defect article, wherein the
intermediate task comprises a task of replacing the second article
with a respective non-defect article.
According to one embodiment, the evaluating comprises determining
that the distance of the automatic mechanical material handling
equipment to the second article is higher than a maximum reachable
distance for having access to the second article, wherein the
intermediate task comprises controlling the automatic mechanical
material handling equipment to move close to the second article to
form a distance smaller than the maximum reachable distance.
According to one embodiment, the control system is a multiprocessor
system, wherein the step of controlling the automatic mechanical
material handling equipment to move the first article and the steps
of evaluating and assigning are executed by at least two processors
of the multiprocessor system.
According to one embodiment, the material handling storage system
comprises at least one pallet rack having at least one front
storage bin and one back storage bin in a front-to-back depth of
the pallet rack, wherein the second article is stored in the back
storage bin and is blocked for movement by the third article stored
in the front storage bin, wherein the first intermediate task
comprises moving the third article.
It is understood that one or more of the aforementioned embodiments
may be combined as long as the combined embodiments are not
mutually exclusive.
FIG. 1 is a schematic diagram illustrating a storage system 100
e.g. a warehouse. The storage system 100 comprises an automated
lift truck (referred to as a lift truck below) or automated guide
vehicle 105 that is configured to move in an aisle 104 between
material handling storage systems 101 of a storage area of the
storage system 100. The lift truck 105 may be guided by a camera
e.g. multi-head camera system that uses fixed points of reference
to move articles throughout the storage area. In other examples,
the lift truck 105 may use lasers, tape, wire or magnets for
guidance.
Material handling system 101 may comprise, for example, a pallet
rack or any storage structure that may store articles or materials.
The material handling storage system 101 may comprise multi-depth
storage bins for storing articles Aij, Bij. For simplification of
the description, FIG. 1 shows only two storage depths, the first
storage depth comprises articles A2i and the second storage depth
comprises articles A1i. However, more storage depths may be
appreciated.
The storage system 100 may further comprise a programmable logic
controller (PLC) 108. The PLC 108 may be part of the lift truck 105
or may not be part of the lift truck 205 e.g. the PLC may be
connected to the lift truck 105 via a connection such as a serial
link or Ethernet or the like.
The PLC may be a programmable controller, an intelligent relay, a
control relay, or another intelligent or microprocessor-based
device used for controlling, automating and/or monitoring a data
(e.g. industrial) process.
The PLC 108 is connected to a hardware interface 115 of a control
system 113 such that for example a communication (e.g. telegram
communication) on link or connection 107 may be performed between
the control system 113 and the PLC 108 e.g. by a predefined
communication protocol. The connection 107 between the hardware
interface 115 and the PLC may be a wireline and/or wireless
connection. For example, the connection may comprise a serial link,
an Ethernet connection, WIFI, Bluetooth or any other connection
enabling exchange of data, signals and/or instructions between the
PLC and the control system 113.
The control system 113 may comprise a computer, smartphone, PDA,
smart TV, smart watch smart glasses, a Mobile Data Entry system
etc.
The control system 113 uses a processor 117 to control the lift
truck 105 via the PLC e.g. controlling the lift truck 105 to
perform a task comprises controlling the PLC 108 such that the PLC
108 controls the lift truck 105 to perform the task.
The control system 113 shown in FIG. 1 is representative. Multiple
processors and computer systems may be used to represent the
functionality illustrated by this single control system 113. The
control system 113 comprises the hardware interface 115 which
allows the processor 117 to send and receive messages to components
of the lift truck 105. The processor 117 is also connected to a
user interface 119, computer storage 121, and computer memory
123.
Computer storage 121 is shown as containing data 125 indicative of
the material handling storage system 101. For example, the data 125
may indicate the position of each storage bin of the material
handling storage system 101 and an indication of the content of
each storage bin, the size or dimension of what is stored in each
storage bin etc. For example, the data 125 may regularly be updated
(e.g. in a periodic basis) or automatically updated as soon as a
change is occurred e.g. to the content of the storage bins or to
the material handling storage system 101 itself. For example, if a
storage bin is emptied, the data may be updated accordingly such
that it indicates that that storage bin has nothing stored
therein.
The storage system 100 may further comprise a camera 132 that is
connected to the control system 113. The camera 132 may be mounted
on the lift truck 105 or on any other support system in the storage
area such that the camera 132 may collect image signals from the
material handling storage system 101. The camera 132 may further be
configured to analyze the collected image signals and to provide
them in the form of the data 125 as a result of the analysis. This
image analysis may be regularly performed in order to update the
data 125 as described above. The camera 132 may for example be the
multi-head camera to guide the lift truck 105 or may be a separate
camera.
The data 125 may be provided by other means as described below.
Program modules 127, may be stored in the computer memory 123.
Program modules 127 generally carry out the functions and/or
methodologies of embodiments of the invention as described
herein.
FIG. 2 is a flow diagram illustrating an example material handling
method in accordance with the present disclosure. For example, an
initial list of tasks may comprise a first and a second access
task. An access task of the first and second access task may be a
task for accessing a respective article Aij, Bij of the material
handling storage system 101. For example, the access task may
comprise moving an article Aij from a given storage bin 103 of the
material handling storage system 101 to a drop-off point, tagging
an article (e.g. by a timestamp indicating the expiration date
unique label to identify and/or provide a quality factor of the
article), or counting one or more articles stored in the material
handling storage system 101. The drop-off point may for example be
another storage bin 103 of the material handling storage system
101.
The initial list of tasks may for example be defined automatically
based, for example, on one or more predefined article access rules
e.g. an article is to be moved from its storage bin to another
storage bin if a certain storage time limit of the article is
reached or to change the quality factor associated with the article
if the article was stored for a long predefined time period in the
same storage bin. The article access rule may comprise, for
example, a stock removal rule that uses a LIFO and/or FIFO
strategies. In another example, the list of tasks may be received
from a user of the control system 113 e.g. in the form of orders or
commands. For example, a task of the list of tasks may be tagged as
being performed or not performed. The first and second access tasks
may be assigned a first and a second execution priority
respectively. For example, the first execution priority is higher
than the second execution priority.
For simplicity of the description only two access tasks are
described; however the skilled person in the art would appreciate
that more than two tasks may be used.
In block 201, at time Ti0, the control system 113 may determine or
identify one of the first and second access tasks having the
highest priority and may control the lift truck 105 to perform the
first access task in block 203A. The control of the lift truck 105
may comprise sending a control signal to the PLC that in turns
translates the received control signal into commands (such as
switching on or off certain elements of the lift truck 105) to be
executed by the lift truck 105.
The lift truck 105 may start at time Ti1 to perform the first
access task to the respective first article. In parallel to
performing the first access task, the control system 113 may
determine the subsequent access task having the subsequent
execution priority to be performed (block 203B), which is, in this
case, the second access task. And, the control system 113 may
evaluate (block 203B) the data 125 for determining that a first
intermediate task is to be performed before the second access task
is performed. In other terms, the second access task depends on the
first intermediate task. FIGS. 4-5 provide different example
methods for the evaluation of the data 125 for identifying
intermediate tasks.
The control system 113 may thus assign (block 203C) an execution
priority to the first intermediate task higher than the second
execution priority. The execution of blocks 203B and 203C may last
more or less than the time required to perform the first access
task.
For example, after the first access task is performed, the control
system 113 may receive at time Ti2 a confirmation from the PLC to
indicate that the first access task is performed. In another
example, the control system 113 may detect at time Ti2
automatically that the first access task is performed e.g. using a
motion detector that detects the movement of the lift truck 105.
For example, if the lift truck 105 does not perform any movement
this may be an indication that the first access task is performed
or finished. In another example, the control system 113 may have an
estimated maximum time (e.g. based on empirical data) that is
required for performing the first access task by the lift truck
105. The expiration of the estimated maximum time may be an
indication that the first access task is performed.
At or after time Ti2, the control system 113 may determine (block
205) that the first intermediate task has the highest priority
among remaining access tasks in the list of tasks (i.e. the first
intermediate access task and the second access task). The control
system 113 may then control the lift truck 105 to perform the first
intermediate task (block 207).
After determining that the first intermediate task is terminated
(e.g. using methods as described above with respect to the first
access task) the control system 113 may determine (block 209) that
the second access task is the task having the highest priority and
may control the lift truck 105 to perform the second access task
(block 211).
The principle of determining in advance whether there is a
dependent task or not may be done in parallel to every running task
by the lift truck 105. For example, if the list of tasks comprises
access tasks A1, A2, A3 that have to be performed in that order.
When performing the task A1 by the lift truck 105, the control
system 113 may determine the next task as A2 and may check whether
this task A2 is dependent or not from an intermediated task that
has to be performed e.g. before A2. In this case the priorities may
be changed such that the intermediate task may have higher priority
than A2. Also, in parallel to performing by the lift truck 105
either the second access task A2 (or the intermediate task) the
control system 113 may determine the next task as A3 and may check
whether this task A3 is dependent or not from an intermediated task
and so on.
FIG. 3 is a flow diagram illustrating another example material
handling method in accordance with the present disclosure, wherein
the initial list of tasks may further comprise a third access task
for accessing a third article. The third access is assigned a lower
execution priority than the second execution priority.
The second access task may for example comprise an initialization
and an execution phase. In case the second access task comprises
moving the second article from its storage bin, the initialization
phase may be the phase during which the lift truck 105 moves toward
the second article and the execution phase may be the phase during
which the lift truck 105 may move the second article.
In parallel to performing the second access task (block 211 of FIG.
2), the control system 113 may evaluate (block 301) the data 125
for determining that a second intermediate task is to be performed
before the third access task; and that the second intermediate task
is dependent of the first intermediate task such that the second
intermediate task is to be performed after the first intermediate
task and before the second access task.
Further, the control system 113 may determine (block 301) that the
second access task is in the initialization phase (e.g. not
effectively executed) and may immediately pause (or interrupt
execution of) the lift truck 105 such that the control system 113
may reorganize the tasks in the right orders as follows.
The control system 113 may assign (in block 303) an execution
priority to the second intermediate task that is higher than the
second execution priority. This step of assigning an execution
priority to the second intermediate task may alternatively be
performed before the lift truck 105 is paused.
Next, the control system 113 may determine (block 305) that the
second intermediate task is the task having the highest priority
and may control the lift truck 105 to perform the second
intermediated task (block 307).
Upon determining that the second intermediate task is terminated,
the control system 113 may determine (block 309) that the second
access task is the task having the highest priority and may control
the lift truck 105 to perform the second access task (block
311).
Upon determining that the second access task is terminated, the
control system 113 may determine (block 313) that the third access
task is the task having the highest priority and may control the
lift truck 105 to perform the third access task (block 315).
FIG. 4 is a flowchart of an exemplary method for evaluating the
data 125.
In step 401, the control system 113 may prompt a user of the
control system 113 for a feedback on the second access task using
the data 125. For example, the control system may display on a
display of the control system a map of the storage bins, their
contents and an indication of the second access task e.g. a line
indicating the movement path of the second article.
In step 403, the control system 113 may receive from the user a
feedback indicating the first intermediate task.
FIG. 5 is a flowchart of an exemplary method for evaluating the
data 125 e.g. as performed in block 203B. For example, the second
access task comprises moving the second article e.g. All from a
first storage bin where it is stored to a second storage bin e.g.
an empty storage bin of the material handling storage systems
101.
In step 501, the control system 113 may determine the movement path
along which the second article A11 is to be moved to the second
storage bin e.g. using the data 125 that indicates the position of
each storage bins including the second storage bin.
In step 503, the control system 113 may use the data 125 for
determining that at least a third article A21 is stored in a
storage bin that it is on the movement path i.e. A21 is blocking
the movement of A11.
In step 505, the control system 113 may define the intermediate
task as a task for moving the third article A21 out of the movement
path e.g. to another storage bin.
FIG. 6 illustrates a method for picking handling units from a
multi-depth storage bins.
The lift truck 105 may operate in an aisle 604 e.g. such as 104 of
FIG. 1. The lift truck 105 may be configured to pick handling units
(HUs) that are not blocked by other HUs. In the example of FIG. 6,
the lift truck 105 may directly pick HU 440 from storage bin 603.1.
For this HU 440 no other HU is in front. However, HU 36 on storage
bin 603.2 cannot be picked directly. Here, HU 62 is blocking HU
36.
In such a case, the control system 113 may automatically detect
that HU 62 is blocking HU 36. Therefore, a stock transfer for HU 62
(the stock transfer is an example of the first or second
intermediate tasks described above) has to be created prior to
picking HU 36. After a task for the stock transfer for HU 62 has
been created it has to be executed by the lift truck 105. FIG. 6
also shows the execution flow 605:
In order to reduce the idle time of the lift truck 105 when picking
the HU 62, the present method may separate the stock transfer task
determination from its execution from a time perspective. Instead
of determining the need of stock transfer just before task
execution (i.e. stock removal) the control system 113 may
"anticipate" the need of future stock transfers earlier.
In this case, the anticipation means that after the execution of
the last step of a previous task, additional actions shall be
triggered. The last step of the previous task may be for example
moving HU 440 from a given storage bin to a destination storage
bin. This last step is also triggered by the control system 113.
The control system 113 may control the PLC (i.e. to control the
lift truck 105) to move HU 440 from a source to a destination
storage bin. Next, the lift truck 105 executes this task. In this
case, the control system 113 may not send new tasks to the lift
truck 105 until the PLC confirms the previous task (i.e. that the
previous task is finished). In other words, after sending the task
(at time t1) to move the HU 440 from the source to the destination
storage bin, the processing in the control system 113 is not time
critical because the lift truck 105 does not wait for a task from
the control system 113. Instead the lift truck 105 is busy at this
point in time (i.e. between t1 and t1') by performing the previous
task.
In this period (between t1 and t1') of time the control system 113
may check what has to be executed next by the lift truck 105 based
on execution priorities. If the next task is also a stock removal
e.g. moving or picking HU 36, the control system 113 checks at this
point in time whether the HU 36 to be picked can be removed
directly e.g. using data indicative of the storage bins such as
data 125. If it is blocked by another HU e.g. HU 62, an automatic
stock transfer (i.e. an intermediate task) is needed. In this case,
a task for the stock transfer of HU 62 is created between t1 and
t1'. So, the creation of the stock transfer task is not time
critical. Later on, when the lift truck 105 finished the previous
task e.g. at t2 the next task is determined. Due to the prior
creation of an automated stock transfer task its task is found now
with higher priority. The stock transfer task does not have to be
created at this time critical moment e.g. at t2; instead, it was
created before and can be sent directly to the lift truck 105.
Accordingly, time is saved and the lift truck has less idle times.
Finally, this increases the performance of the storage system.
With the present method the additional time needed by the creation
of the stock transfer task may be saved. In diagram 605 it can be
seen that between t1 and t2 already the determination of the next
task and the creation of a stock transfer task takes place. This
means that the same decision is taken and even potential user logic
would be executed, too. By starting the stock transfer task
creation already at t1 idle time of the control system 113 and the
lift truck 105 is reduced. In the time frame from t1 to t1' the
control system determines the next task and creates a stock
transfer task. Additionally, the idle time of the lift truck 105
between t2 and t3 is reduced because fewer actions have to be
executed.
* * * * *